#include<reg51.h>

sbit p1_0=P1^0;
void delay(unsigned char t )
{
	unsigned int i;
	for(;t>0;t--)
		for(i=124;i>0;i--);
}

void main()
{
 	p1_0=0;
	while(1)
	{
		delay(50);
		p1_0=!p1_0;
	}
}